Today, sensor-bearing units are commonly used in a wide range of technical fields, for example in automotive industry and aeronautics. These units provide high quality signals and transmissions, while allowing integration in simpler and more compact apparatus.
Such a sensor-bearing unit generally provides a bearing, an impulse ring, typically a magnetic impulse ring, and detection means facing the impulse ring. The impulse ring provides a target holder and a magnetized target including alternating North and South poles, whose number depends on bearing size, detection precision and particular application. With a bearing having suitable dimensions, the target holder may be fixed to a rotating ring of this bearing, while the detection means may be fixed to a non-rotating ring of this bearing or to a fixed casing.
The magnetized target is made from a magnetized material and is attached to a tubular portion of the target holder. Such a design is known from FR-A-2 884 367, in which the target holder provides an inner portion, which is attached to the inner ring of a bearing, a radial portion, and an outer tubular portion, which holds the magnetic target. The radial portion and the outer tubular portion form a right angle, which can be damaged in case of high rotation speeds, for example above 20 000 rotations per minute (rpm) and vibrations during operation of the impulse ring. In addition, the radial portion of the target holder provides a portion axially offset to avoid interferences with outer ring, but the specific shape increases the necessary space to integrate the sensor-bearing unit.